[(1,2,5,6-η)-Cycloocta-1,5-diene](4-isopropyl-1-methyl-1,2,4-triazol-5-ylidene)(triphenylphosphane)iridium(I) tetrafluoridoborate dichloromethane 0.8-solvate

The central IrI atom of the cationic complex of the title compound, [Ir(C8H12)(C18H15P)(C6H11N3)][BF4] ·0.8CH2Cl2, exhibits a distorted square-planar coordination environment.

A new triazole-based N-heterocyclic carbene iridium(I) cationic complex with a tetrafluoridoborate counter-anion, [Ir(C 8 H 12 )(C 18 H 15 P)(C 6 H 11 N 3 )]BF 4 Á-0.8CH 2 Cl 2 , has been synthesized and structurally characterized. The central Ir I atom of the cationic complex has a distorted square-planar coordination environment, formed by a bidentate cycloocta-1,5-diene (COD) ligand, an Nheterocyclic carbene, and a triphenylphosphane ligand. The crystal structure comprises C-HÁ Á Á(ring) interactions that orient the phenyl rings; nonclassical hydrogen-bonding interactions between the cationic complex and the tetrafluoridoborate anion are also present. The complex crystallizes in a triclinic unit cell with two structural units and an incorporation of dichloromethane solvate molecules with an occupancy of 0.8.
The molecular structure of the title complex 2, shown in Fig. 1, is characterized as an Ir I cationic complex with a tetrafluoridoborate counter-ion, with partial incorporation of dichloromethane solvate molecules (s.o.f. 0.8). The distorted square-planar environment around the Ir I atom is defined by the bidentate cycloocta-1,5-diene (COD) ligand, the carbene C1 atom of the triazole NHC ligand, and the P atom of the triphenylphosphane ligand. The P1-Ir1-C1 bond angle is 93.88 (10) . The N1-C1-N3 bond angle of the coordinating carbene atom significantly differs with a value of 103.3 (3) from the expected sp 2 hybridization.
The crystal packing of the title compound is displayed in Fig. 2. There are several non-classical hydrogen-bonding interactions between the cation and anion that orient the [BF 4 ] À group. Additionally, there are non-classical intermolecular hydrogen-bonding interactions between the hydrogen atom of a phenyl group (H10) and a nitrogen atom of the NHC ligand (N2). Non-classical hydrogen bonding interactions are shown as dotted green lines in Fig. 2, and their numerical data summarized in Table 1. Notably absent are hydrogen-bonding interactions with the dichloromethane solvate. The lack of hydrogen-bonding interactions involving the solvate may contribute to its partial occupancy.

Figure 3
View of the title compound 2 showing perpendicular ring orientations arising from C-HÁ Á Á(ring) interactions (shown as dashed orange lines).

Figure 1
The molecular entities in the crystal structure of the title compound 2. Displacement ellipsoids are drawn at the 50% probability level.

Refinement
Crystal data, data collection, and structure refinement details are summarized in Table 2.

Figure 4
Reaction scheme for the synthesis of the title compound 2.  Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.